August 2023

Q. The parallel resistance-capacitance bridge shown below has a standard capacitance value of C1=0.1µF and a resistance value of R3=10 kΩ. The bridge is balanced at a supply frequency of 100 Hz for R1=375 kΩ, R3=10 kΩ and R4=14.7 kΩ. The value of the dissipation factor 𝐷 = 1/(𝜔𝑅𝑝𝐶𝑝) of the parallel combination of 𝐶𝑝 […]

Q. In the circuit shown below, all OPAMPS are ideal. The current 𝐼 = 0 A when the resistance 𝑅 =________________𝑘Ω. Ans: 9 – 9.1 Sol:

Q. In the circuit shown below, all transistors are n-channel enhancement mode MOSFETs. They are identical and are biased to operate in saturation mode. Ignoring channel length modulation, the output voltage Vout is __________. Ans: 4 Sol: By using the current mirror concept current flow in 4 kΩ branch will be 1 mA.

Q. The transfer function relating the input 𝑥(𝑡) to the output 𝑦(𝑡) of a system is given by G(s) = 1 (s + 3) . A unit-step input is applied to the system at time t = 0 . Assuming that 𝑦(0) = 3, the value of 𝑦(𝑡) at time 𝑡 = 1 is         (Answer

Q. In the circuit shown below, the angular frequency 𝜔 at which the current is in phase with the voltage is_____________rad/s. Ans: 20000 Sol: For the given parallel RLC circuit, current will be in phase with the voltage when circuit operate at resonant frequency. Resonant frequency in parallel RLC circuit,

Q. In the circuit shown below, a step input voltage of magnitude 5 V is applied at node A at time 𝑡 = 0. If the capacitor has no charge for t £ 0 , the voltage at node P at 𝑡 = 6 𝜇s is_____________V. (Answer should be rounded off to two decimal places)

Q. Four identical resistive strain gauges with gauge factor of 2.0 are used in a Wheatstone bridge as shown in the figure below. Only one of the strain gauges 𝑅𝑆𝐸𝑁𝑆𝐸 changes its resistance due to strain. If the output voltage 𝑉𝑂𝑈𝑇 is measured to be 1 mV, the magnitude of strain, in units of microstrain,

Q. A pulsed laser emits rectangular pulses of width 1 nanosecond at a repetition rate of 1 kHz. If the average power output is 1 mW, the average power over a single pulse duration, in watts, is              (A) 1               (B) 10                          (C) 100                        (D) 1000 Ans: 1000 Sol: The underlying concept here to be

Q. A pulsed laser emits rectangular pulses of width 1 nanosecond at a repetition rate of 1 kHz. If the average power output is 1 mW, the average power over a single pulse duration, in watts, is              (A) 1               (B) 10                          (C) 100                        (D) 1000 Ans: 1000 Sol: The underlying concept here to be

Q. A resistance-meter has five measurement range-settings between 200 Ω and 2 MΩ in multiples of 10. The meter measures resistance of a device by measuring a full-range voltage of 2 V across the device by passing an appropriate constant current for each range-setting. If a device having a resistance value in the range 8